With the lite raspbian I only get two lighten leds - a green and a red next to the power supply - no light near the ethernet
I'd assume a solid green means what it does on a Pi 2 -- but there is an easy way to test: Take the card out and plug in the pi. This will not do any harm, but obviously it will not work either. Most likely you will see exactly what you are seeing now: Solid red and green, no ethernet lights.
This means the Pi did not find a card with a valid MBR, and it will respond exactly as if there were no card at all.
With the normal raspbian I only get a red light next to the micro-usb and that's it
Unless the green light at least flickers a bit a first, this may be a variation on the previous scenario. To explain:
If it flickers intermittently for a number of seconds, this indicates the firmware and bootloader worked and the kernel started; all these things are on the first partition. Normal boot time might be anywhere from 5-20 seconds, although the first boot may be considerably longer as I have noticed it may wait on some configuration during this time.
However, if the kernel hangs for some reason, this period of activity may be very brief, less than two seconds.
If it begins flashing in a regular pulse at about 1-2 Hz, it is indicating there was an issue with loading either the firmware, bootloader, or kernel. On newer models I think this pattern of (3-8) flashes will repeat endlessly after a brief pause, on older ones it may happen only once (this may also depend on the firmware, which is loaded first, i.e., if it repeats it is probably closer to 8 than 3 flashes; the number indicates the nature of the problem, the lower the number the earlier in the boot process the problem occurred).
Obviously this is not what is happening here, however.
I would do the test with no SD card and see which way it responds -- solid green or no green. It is probably the former, and the latter may be a kernel hang happening before it can access anything on the second (root filesystem) partition.
Note that the "lite" and normal images are identical with regard to the aspects just described. Put another way, it is not a matter of both of them being correctly installed but encountering different problems. It is a matter of one of them being installed completely wrong, such that the card might as well be blank.
You did not describe how you put the images on the cards. This should not be a difficult process, but it does seem to snare some people at first, particularly if they have used a MS Windows based methodology.
Finally, there there are kinds of cards that just don't work, although I think an 8GB Sandisk should be fine. If both the cards are identical, try a different one (anything you can fit an image on). If you have the same problems, it is very unlikely to be the kind of card.
Which ever scenario does not match the "no card" one (again, probably this is the no green light one), you need to plug the pi into an HDMI TV or monitor to see what happens. If you have a friend, relative, TV at work/school/anywhere you can access for two minutes this is simple.